<template>

  <div class="app-container">

    <h2 style="text-align: center;">发布新课程</h2>

    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="提交审核"/>
    </el-steps>

    <el-form label-width="120px">
      <el-form-item label="课程标题">
        <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
      </el-form-item>

      <!-- 所属分类：级联下拉列表 -->
      <!-- 一级分类 -->
      <el-form-item label="课程类别">
        <el-select
          v-model="courseInfo.subjectParentId"
          placeholder="一级分类"
          @change="subjectLevelOneChanged">
          <el-option
            v-for="subject in subjectNestedList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
        <!-- 二级分类 -->
        <el-select v-model="courseInfo.subjectId" placeholder="二级分类">
          <el-option
            v-for="subject in subSubjectList"
            :key="subject.value"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
      </el-form-item>

      <!-- 课程讲师 -->
      <el-form-item label="课程讲师">
        <el-select
          v-model="courseInfo.teacherId"
          placeholder="请选择">
          <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"/>
        </el-select>
      </el-form-item>

      <el-form-item label="总课时">
        <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
      </el-form-item>

      <!-- 课程简介  -->
      <!-- 课程简介-->
      <el-form-item label="课程简介">
        <tinymce :height="300" v-model="courseInfo.description"/>
      </el-form-item>

      <!-- 课程封面-->
      <el-form-item label="课程封面">

        <el-upload
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload"
          :action="BASE_API+'/eduoss/file/upload'"
          class="avatar-uploader">
          <img :src="courseInfo.cover">
        </el-upload>

      </el-form-item>
      <el-form-item label="课程价格">
        <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/>
        元
      </el-form-item>
      <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
      </el-form-item>
    </el-form>
  </div>
</template>
<style scoped>
  .tinymce-container {
    line-height: 29px;
  }
</style>
<script>
  import course from '@/api/edu/course.js'
  import subject from '@/api/edu/subject.js'
  import teacher from '@/api/edu/teacher'
  import Tinymce from '@/components/Tinymce'

  const defaultForm = {
    title: '',
    subjectId: '',
    subjectParentId: '',
    teacherId: '',
    lessonNum: 0,
    description: '',
    cover: process.env.OSS_PATH + '/data/doc/e-learning/%E9%BB%98%E8%AE%A4%E8%AF%BE%E7%A8%8B%E5%9B%BE%E7%89%87.jpg',
    price: 0
  }
  export default {
    components: { Tinymce },
    data() {
      return {
        courseInfo: defaultForm,
        saveBtnDisabled: false, // 保存按钮是否禁用
        teacherList: [],
        subjectNestedList: [], // 一级分类列表
        subSubjectList: [], // 二级分类列表
        BASE_API: process.env.BASE_API // 接口API地址
      }
    },
    watch: {
      $route(to, from) {
        this.init()
      }
    },
    created() {
      this.init()
    },

    methods: {
      init() {
        if (this.$route.params && this.$route.params.id) {
          const courseId = this.$route.params.id
          this.getCourseInfo(courseId)
        } else {
          this.courseInfo = { ...defaultForm }
          this.getTeacherList()
          this.initSubjectList()
        }
      },
      // 获取课程信息
      getCourseInfo(courseId) {
        course.getCourseInfo(courseId)
          .then(response => {
            this.courseInfo = response.data.itmes
            // 查询所有分类。包括一级和二级分类
            subject.getNestedTreeList().then(response => {
              // 获取所有一级分类
              this.subjectNestedList = response.data.items
              for (var i = 0; i < this.subjectNestedList.length; i++) {
                // 获取一级分类
                var oneSubject = this.subjectNestedList[i]
                // 如果当前课程信息的分类id等于当前一级分类，则取出当前一级分类的二级分类
                if (this.courseInfo.subjectParentId == oneSubject.id) {
                  this.subSubjectList = oneSubject.children
                }
              }
            })
            // 获取所有老师
            this.getTeacherList()
          })
      },
      // 上传成功之后调用的方法
      handleAvatarSuccess(res, file) {
        console.log(res)// 上传响应
        console.log(URL.createObjectURL(file.raw))// base64编码
        this.courseInfo.cover = res.data.url
      },
      // 上传之前调用的方法
      beforeAvatarUpload(file) {
        // const isJPG = file.type === 'image/jpeg'
        const isLt2M = file.size / 1024 / 1024 < 2

        // if (!isJPG) {
        //   this.$message.error('上传头像图片只能是 JPG 格式!')
        // }
        if (!isLt2M) {
          this.$message.error('上传头像图片大小不能超过 2MB!')
        }
        return isLt2M
      },
      // 二级联动
      subjectLevelOneChanged(value) {
        // 遍历所有分类，包含一级分类和二级分类
        for (let i = 0; i < this.subjectNestedList.length; i++) {
          // 获取选中的一级分类下的二级分类
          if (value == this.subjectNestedList[i].id) {
            // 从一级分类中获取二级分类
            this.subSubjectList = this.subjectNestedList[i].children
            this.courseInfo.subjectId = ''
          }
        }
      },
      // 获取课程分类
      initSubjectList() {
        subject.getNestedTreeList().then(response => {
          this.subjectNestedList = response.data.items
        })
      },
      // 获取所有老师
      getTeacherList() {
        teacher.getList().then(response => {
          this.teacherList = response.data.items
        })
      },
      // 添加
      addCourseInfo() {
        course.addCourseInfo(this.courseInfo)
          .then(response => {
            this.$message({
              type: 'success',
              message: '保存成功！'
            })
            return response
          })
          .then(response => {
            this.$router.push({ path: '/edu/course/chapter/' + response.data.courseId })
          })
          .catch(response => {
            this.$message({
              type: 'error',
              message: response.message
            })
          })
      },
      // 修改
      updateCourseInfo() {
        course.updateCourseInfo(this.courseInfo)
          .then(response => {
            this.$message({
              type: 'success',
              message: '修改信息成功！'
            })
            return response
          })
          .then(response => {
            this.$router.push({ path: '/edu/course/chapter/' + response.data.courseId })
          })
          .catch(response => {
            this.$message({
              type: 'error',
              message: response.message
            })
          })
      },
      // 保存或者修改
      saveOrUpdate() {
        if (!this.courseInfo.id) {
          //添加
          this.addCourseInfo()
        } else {
          // 修改
          this.updateCourseInfo()
        }
      }
    }
  }
</script>
